Hey, every read about the Kimber Solo Carry and it's defective safety? I hear you can fire a round even with the safety engaged sometimes. I'm sure that isn't the only gun in history to have safety issues. If the weapon involved was A kimber solo carry and within the serial numbers of the affected guns, it sure could go a long way to a defense of negligence.
Unless you want to argue that carrying a weapon in itself is negligent, you will have to have more than: somebody got shot, to lay culpability and resulting negligence on the gun carrier.